a. Besides authentication, what security benefit does a digital signature provide? b. Explain what this benefit means. c. Do most message-by-message authentication methods provide message integrity as...

a. Besides authentication, what security benefit does a digital signature provide? b. Explain what this benefit means. c. Do most message-by-message authentication methods provide message integrity as a by-product?

a. Contrast the key the sender uses for encryption in public key encryption for confidentiality and public key encryption for authentication. b. Contrast the key the receiver uses for decryption in public key encryption for confidentiality and public key encryption for authentication. (Careful!)